Document Type : Research Article


Department of Applied Physics, Delhi Technological University, Delhi, 110042, India


The effects of ZnO nanoparticle coating on the physicochemical and electrochemical properties of LiFePO4 (LFP) have been investigated in this work. ZnO-modified LiFePO4 cathode materials were synthesized via sol-gel and modified by ZnO nanoparticle using ball mill method. The amount of ZnO additive is chosen as a controlling factor to tune ZnO content over the surface of LFP particles. Structure and morphology of the LFP material with and without ZnO-coating layer were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectra. The XRD patterns reveal that the proper phase of LFP is formed with the ordered olivine-type orthorhombic structure of Pnma space group, and no impurity phase like LiZnPO4 has been noticed. AC conductivity measurements have shown that the ZnO-modified LFP samples significantly assists in lowering the resistance of cathode active material and enhancing the conductivity. It is found that the 2.5 wt% ZnO-doped LFP exhibits the highest conductivity than the 5 wt% ZnO and 1 wt% ZnO doped LFP or the un-doped sample. Among the synthesized samples, LFPZ2.5 displays highest discharge capacity 160 (±5) mAhg-1 (~94% of the theoretical capacity of LiFePO4) at 0.1C rate. These results indicate that 2.5 wt% ZnO coated pristine LFP sample proves to be alternative material for automotive industry and it may be possible alternate of cathode materials in hybrid electric vehicles. Copyright © 2016 VBRI Press